Last updated: October 12, 2026
Peptides·Index is a price tracker for research peptides. We collect listings from research-peptide vendors, put each one on the same footing (cost per milligram), and show them side by side so you can see who charges what before you buy. Alongside the tracker we publish guides that explain what these compounds are and what the research says about them.
The site is free to use. It earns money mainly through affiliate commissions, all of which are explained in full below.
What you'll find here#
- The price tracker. Every compound in our catalog has a price page listing each vendor we track, with the price, size, cost per mg, stock status and any certificate of analysis (COA) we hold for that listing.
- Vendor pages and comparisons. Where each vendor stands on price, testing documentation and shipping.
- Guides and tools. Plain-language explainers, buying guides and utilities such as the reconstitution calculator.
How prices are collected#
Prices are refreshed automatically on a schedule that runs every 6 hours. Some vendors send us a structured product feed; for the rest we read the prices published on their own stores. Each refresh records the price, size, stock status and the vendor's own product link. Certificates of analysis are collected on a separate weekly schedule.
Where a vendor offers our readers a discount code, or runs a site-wide promotion, the price we show is the price after that discount. Price history charts keep the list price so the trend stays comparable over time.
When a size, count or test result can't be read reliably from a listing, we leave it blank rather than guess. A missing number is less harmful than a wrong one.
How cost per mg works#
Sticker prices hide the real value, because vials come in different sizes. We divide each listing's price by the total milligrams it contains, which gives a cost per mg you can compare across vendors and vial sizes. Compounds sold by international units, such as hCG, are compared per IU instead. Our cost per mg guide walks through the maths.
We only compare cost per mg within one product-form group. Injectables (vials), orals (capsules and tablets together) and sprays are each compared only against their own group. A milligram in a capsule and a milligram in a lyophilized vial aren't the same kind of quantity, so pooling them would produce misleading numbers. Multi-vial kits are shown as extra pricing detail; the ranking itself uses the single-unit price.
How vendors are listed#
We list vendors whose prices we can track reliably. Vendors can also apply through our vendor page. Applying is free. If we approve an application, the vendor:
- pays a one-time onboarding and integration fee;
- agrees to pay us a cash commission on sales we refer;
- sets up a referral link for our readers, with a reader discount if it chooses to offer one (the discount can be 0%);
- connects a product feed we can read and, for most stores, an order-reporting feed and a test order, so we can confirm which orders we referred.
We can pause or remove a vendor at any time, for example when its prices stop updating or we learn of a problem with its products.
Certificates of analysis (COAs)#
Many vendors publish COAs from third-party testing labs. We collect them and attach each one to the listing it covers. For the labs whose records we can query directly (currently ILS Laboratories, Freedom Diagnostics and Vanguard Laboratory), we check the certificate against the lab's own system. The lab's client name has to match the vendor, and where the certificate came from a vendor's listing, the lot number has to match too. When the lab's record and the vendor's PDF disagree, we publish the lab's figures.
A few limits apply:
- We don't test products ourselves. A COA is the lab's result for one batch, as reported by that lab.
- A COA for one lot says nothing certain about a different lot.
- Certificates from other labs can only be shown as the vendor supplied them.
If we learn of a failed independent test or another serious safety finding for a vendor we list, we report it, including for vendors we have an affiliate relationship with.
How we make money#
Peptides·Index earns money from the links and offers on this site. Here is every way it does:
- Vendor commissions. When you follow a link to a vendor and buy something, that vendor may pay us a commission. You don't pay more because of it, and where a vendor has set up a reader discount, you pay less.
- Vendor onboarding fees. Approved vendors pay a one-time onboarding and integration fee, as described above.
- Amazon. Some supply and product links go to Amazon. As an Amazon Associate we earn from qualifying purchases.
- Other referral programs. Our link-in-bio pages include referral links to other services (for example, a peptide reference site, a bloodwork service and a sleep and recovery tracking app). We may earn a commission or credit when you sign up through them.
How listings are ordered#
We want you to be able to tell a straight price ranking apart from a highlighted listing. Here is how each part of the site decides what comes first:
- The full price table on each compound's page is sorted by cost per mg, after any reader discount, within each product-form group. A commission, a partnership or an onboarding fee doesn't change that order. If two listings cost exactly the same per mg, our vendor ranking breaks the tie.
- Highlighted listings (the pick at the top of each price page, the vendors suggested in stack quiz results and the Featured deals on the home page) are chosen on a combination of factors: whether the listing has a lab certificate on file and how thorough that testing is, whether it's in stock, how long the vendor has been in business, and the vendor's public and social presence. Price is part of it, so a highlighted listing isn't always the cheapest one. Some vendors that appear in these spots are affiliate partners, including Peptide Supply Co.
Discount codes appear on our price pages, buy buttons, link-in-bio pages and social posts. We only show codes that vendors have set up for our readers.
Editorial independence#
Our guides are written to be useful first. Vendors don't review or approve our articles before they're published, and we don't accept payment to publish a review or to change a verdict. When we recommend a vendor, we explain why, and we include material safety findings even when they concern a vendor that pays us.
Medical and scientific claims in our guides link to their sources, usually peer-reviewed studies on PubMed, so you can check them yourself. If you find a mistake, tell us and we'll fix it.
Research use only#
The compounds tracked on this site are sold by vendors as research chemicals, not for human consumption. Most are not approved by the U.S. Food and Drug Administration for any human use. Nothing on Peptides·Index is medical advice, a recommendation to use any compound in people, or a dosing instruction for treatment. Please talk to a qualified healthcare professional before making any health decision.
Contact us#
Questions, corrections, or a vendor that should be listed? Use our contact form. For how we handle your information, see our Privacy Policy; the rules for using the site are in our Terms of Use.